Guarantees and Commitments (Financing Commitments) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Guarantees and Product Warranties [Abstract]
Unused revolving credit line commitments and other	$ 6,337	$ 6,142
Commitments to provide capital to investees	1,069	778
Mortgage loan origination commitments	708	760
Home equity lines of credit	168	187
Construction-lending commitments	53	101
Unconditionally cancelable unfunded commitments	$ 26,700	$ 20,300